Sisterly Love: Reflections on Twinship

Identical twins are fascinating, not only to their parents but also to the public. On a daily basis, people on the street inquire about my daughters, from elementary school kids who assert, “They look like the same person!” to adults who say, “I always wanted to have twins.”

At almost five-years-old, M. and S. know they are twins, but they have only a vague understanding of how that relationship differs from other sibling relationships. Recently, as S. signed her name one day, she told me:

“S-A-M, that spells Sam.”

I asked, “Do your friends at school call you Sam instead of Samira?”

“No,” she replied. “They call me [M.]”

“Why do they do that?”

“Because they’re silly.”

S. thinks her friends are silly because she does not believe she and her sister look alike. Indeed, not all twins do, with fraternal/sororal twins (originating from separate fertilized eggs) being the more common type of multiple. My husband and I believed our daughters were sororal twins until they were six months old because that is what our obstetricians told us they were. Our girls were “di/di” in utero, which means that they had separate amniotic sacs and separate placentas. Most “di/di” twins are fraternal/sororal, while many identical twins share a placenta and possibly even the amniotic sac.

When our girls turned out to have the same recessive blood type and red hair color (a surprise to the South Asian side of the family), people started asking us if they were identical. So, we shelled out a fair amount of money for a DNA test to tell us what we seemed incapable of realizing for ourselves: “[T]here is greater than a 99% probability that the twins are monozygotic.”

Without that piece of paper, I might have been living in denial today — I have seen more than a few examples of parents being the last to know that their very-similar-looking twins are identical. As parents, we are attuned to seeing small differences in our children’s appearances, and so we make ourselves believe that differing birthmarks and slight differences in weights or heights are irrefutable signs of different underlying genes. The truth is that so-called identical twins aren’t really identical in every way, one of the many interesting aspects of twinning/twinship.

For those who are curious about this special sibling relationship, I recommend reading Abigail Pogrebin’sOne and The Same. This non-fiction book is a mixture of memoir and interviews, a compilation of Pogrebin’s reflections on her own experience as an identical twin, profiles of other sets of twins, and conversations with experts on the science behind, and social aspects of, twinning and twinship. It is a well-researched, intimate look at the twin relationship that delves into the positives of closeness to the negatives of comparisons, competition, and loss. The book explores, for example, how some twins seek to enhance the sameness, while others struggle to differentiate themselves, sometimes to an extreme degree. Monozygotic twins may share the same underlying genes, but how those genes interact with the environment creates individuals who can be, in some cases, as different from each other as any other set of siblings.

This book has influenced the way my husband and I are raising our daughters. We treat them as two separate people who happen to look very much alike. Thus, we encourage them to wear different clothes, have different friends, and engage in different activities, while also encouraging them to spend quality time together and to cherish their sibling bond (without excluding their baby sister).

So far, M. and S. perceive themselves as individuals, and hopefully the rest of the “silly” world will recognize their individuality, too.

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34 thoughts on “Sisterly Love: Reflections on Twinship”

Your daughters are adorable, and this post was great. I will be checking into that book! My husband and I are expecting ID girls (mo-di) in late spring. We’re thrilled to be embarking on the twin journey!

That post is about a very cute children’s book, one I recommend for twins. My girls really loved it (for reminding them they are individuals, even if people often mix them up or treat them like a single unit). They’re reading chapter books now, but they still reference that picture book when they joke about how they’re alike: “almost, almost, but not quite.”

My partner is one of a twin, girl and boy but pretty similar looking, just the fact that they are girl and boy…! I think that it is awesome that you are raising them as their own person, so often I see children who are dressed the same (even non twins) and I really do believe in nurturing their sense of identity and uniqueness.
Interesting post!

Thank you! We’re trying to encourage them to recognize their individuality, but it’s tough sometimes. Right now, we’re struggling with separate playdates and birthday parties, which stem from being in separate classes and having different friends. We want them to spend lots time together outside of school, but they want to spend ALL of their time together. I can’t blame them, though. It’s a close bond.

My twins are clearly VERY most massively extremely fraternal and yet still I get ‘are they identical?’. I don’t use the judgment of others as a helping feature for telling the difference between twins given one of mine is a tall straight haired brunette and the other is a tiny blondie.

The sweetest thing, however, is the bond my twins have. They just do and it is gorgeous to watch…

Raising twins is a lot of fun, isn’t it? I agree that you can rest assured that your adorable twins aren’t identical. There are some people who just can’t tell the difference between even completely unrelated people!

It amazes me when people believe that g/b twins are identical! Are your friend’s twins still infants? When my girls were babies, someone once said, “Oh, you have a boy and a girl! Are they identical?” Apparently, there are some people who believe that b/g twins can share identical genes!

Even ID twins have genetic differences. I like to blow tiny minds by pointing out that epigenetic methylation makes for two different individuals. It’s one way of getting beyond the dreaded ‘are they twins? are they identical? did you deliver by c-section? did you breastfeed? MY children were 12 months apart, that is JUST like having twins’ and so on…

I got the boy and a girl comment a lot, because one twin had stuff all hair for about two years!

It’s so true–so-called identical twins are such different people! If you haven’t read Pogrebin’s book already, I highly recommend it. She features identical twins, but much of what she writes about is applicable to sororal twins, too.

Such a wonderful video! Two of my friends each have their own set of twins–but in both cases they are fraternal. I remember a coworker asking my one friend if her twins were identical, which we laughed about later. Her kids clearly aren’t–not only don’t they look alike but one is a boy and the other is a girl. It seemed like common knowledge to both of us, but it was good reminder that it really isn’t.

Thanks! One of the nice things about having twins is watching babies interact with each other in a loving way. At that age, most babies engage in parallel play and keep a certain distance from playmates they don’t know so well.

It’s funny that your friend is asked if her b/g twins are identical. When my girls were younger, some people would ask if they were a boy and a girl, even after asserting that they look alike.

My mother had an older set of twin sisters and a younger set of twin sisters. I couldn’t tell you if they were identical or not – I’ve never had any difficulty telling them apart.

Actually, from the picture at the top of the post, I wouldn’t have any trouble telling your girls apart either. They are obviously sisters, but also obviously individuals (also cute as buttons, but that’s also obvious).

It’s interesting what different people and different cultures use as differentiating characteristics. In the West we are accustomed to looking at things like hair, eye, and skin color, build, and face shape. In China, where most of those things are fairly uniform, they look at very different things. For the record, most people here think all Caucasians look the same.

It’s always interesting to hear about families with multiple sets of twins. Fraternal twins are more likely to run in families, but it’s certainly possible that your mother’s siblings are identical. Are there other sets of twins in your extended family?

You make a good point about how some people are simply good at recognizing differences between people, while others are not, most especially when interacting with people from different racial groups.

Actually, my maternal grandmother gave birth to three sets of twins, though the first died in childbirth or shortly afterwards – no one was ever very clear on the details. All of them were girls, and all of them, I suspect, sororal twins. In the extended family, even including my Grandmother’s brothers and sisters downwards, there are no other twins that I’m aware of.

Perhaps my Grandmother was part of some secret, Canadian wartime experiment to confuse the Nazis with a whole bunch of twins.

Wow, three sets of twins in the pre-ultrasound days! I imagine that was a surprise. I am sorry to hear that her first set of twins passed away under those circumstances. It’s a risky pregnancy, as I know all too well (my twins were 3+ months premature).

My mom is an identical twin, and as a child I always thought it was strange how many people would get her and her sister confused – they looked very different to me. As I get older, though, I’m constantly amused by the way my mom and her twin will show up somewhere accidentally wearing a similar outfit that they each bought at separate places and without consulting each other, and on the phone even I can’t tell them apart. Twins are definitely fascinating; I’ll have to check out this book. Thanks for the tip!

Funny! My impression is that identical twins are often more alike than they are different. My girls have similar tastes in some things (and I wouldn’t be surprised if they showed up to a future event dressed in the same outfit!), but are very different in other ways (for example, they eat almost entirely different meals). I think Pogrebin’s book would be the most interesting to those of us who are either twins or related to twins. I hope you like it!